Method of Preparing an Oat Protein and Fiber Product

ABSTRACT

A method of preparing an oat protein and fiber product. A base composition is prepared that includes an oat material. The base composition and water are mixed to form a slurry. At least one enzyme is mixed into the slurry. The at least one enzyme facilitates sugar formation and thinning of the slurry. The slurry is cooked to convert the slurry into a first intermediate product having a dextrose equivalent (DE) of between about 20 and 90. The first intermediate product is diluted with water to form a second intermediate product. A decanting centrifuge solids slurry is recovered from the second intermediate product by passing the second intermediate product through a decanting centrifuge. The decanting centrifuge solids slurry is heated. A clarifying centrifuge solids slurry is recovered from the heated decanting centrifuge solids using a clarifying centrifuge. The clarifying centrifuge solids slurry is dried to form a dried product. The dried product has a protein concentration of between about 30 weight percent and about 90 weight percent and a total dietary fiber concentration of less than about 5 weight percent.

FIELD OF THE INVENTION

This application claims priority to U.S. application Ser. No.13/744,325, filed Jan. 17, 2013, and U.S. Provisional Application No.61/587,242, filed Jan. 17, 2012. The contents of which are incorporatedherein by reference.

FIELD OF THE INVENTION

The invention relates generally to an oat-derived food product. Moreparticularly, the invention relates to a method of preparing an oatprotein and fiber product.

BACKGROUND OF THE INVENTION

Consumers are increasingly concerned about purchasing and consumingproducts that the consumers view as being more healthful. For example,products possessing higher levels of complex carbohydrates and fiber,especially soluble fiber, are becoming more popular with consumers.

In addition, products containing lower levels of fat and cholesterol aswell as a decreased caloric content are becoming more popular withconsumers. Many consumers also desire products made from all-naturalcomponents that contain no stabilizers, emulsifiers, or other exogenousadditives, such as refined sugars or artificial sweeteners.

One drawback of food products produced for the health conscious marketis that they tend to be less sweet than conventional food products. Onetechnique that has been used to overcome this drawback and thereby makesuch food products appeal to a greater portion of society is to addsweeteners, such as sucrose, glucose syrup, and high fructose cornsyrup.

Even though the addition of the sweeteners increases the appeal of thefood products to some segments of the health conscious market, theseproducts are not desired by consumers who exclude refined or artificialsweeteners from their diet.

An article by Janet Raloff (Beyond Oat Bran, Food Technology 1991 vol.8, page 62) describes the physiological benefits of consuming anoat-based product, which is identified by the name Oatrim. The oat-basedproduct is formulated from either oat bran or oat flour. The articleindicates that the odorless and nearly tasteless oat-based product isparticularly suited as a fat replacement in low-temperatureapplications, such as frozen confections.

Oat-based food products are described in Inglett, U.S. Pat. Nos.4,996,063 and 5,082,673. A mixture of oats and water is gelatinized bypassage through a steam injection cooker at a temperature of between138° C. and 143° C. After the pH of the mixture is adjusted,alpha-amylase is added to hydrolyze the starch in the mixture.

Once hydrolyzation is complete, soluble fiber is separated from themixture. Finally, the soluble fiber is dehydrated to provide theoat-based food product. Examples in the Inglett patents indicate thatthe oat-based food product is mixed with additional components, such asmilk and sugar, to formulate the frozen confection.

Mitchell et al., U.S. Pat. No. 4,744,992, discloses using a dual enzymemethod, which includes liquefying and saccharifying rice, to produce ahigh glucose syrup. Examples in the Mitchell et al. patent indicate thatwhen the syrup is incorporated into a frozen confection, vegetable oilin a concentration of approximately 10 weight percent of the frozenconfection as well as stabilizers are added to provide the frozenconfection with a creamy texture. Mitchell et al. also indicates thatliquefaction is performed at a temperature of approximately 80° C.

Whalen et al., U.S. Pat. Nos. 6,685,974; 6,589,589; 6,395,314; 5,989,598and 5,723,162, each describe a process for preparing an oat-basedfunctional syrup and then forming an oat-based frozen confection fromthe oat-based functional syrup. The contents of the preceding patentsare expressly incorporated herein by reference.

In addition to the fact that oats have a relatively high proteinconcentration of about 11 weight percent, the oat protein has thehighest nutritive value of the commonly cultivated cereal grains such ascorn (maize), wheat and rice.

For an ingredient to have commercial value for use in supplementformulations by adding significant amounts of protein such as betweenabout 1 and 3 grams and optimally more per serving at common servingsizes such as between about 30 and 55 grams for cereal products andbetween about 240 and 320 grams for beverage products, the ingredientproduct would have to contain a substantial protein concentration.

Even though oats have a high protein concentration, for the oats to meetthe preceding criteria for use in supplement formulations, the oatswould need to be processed to increase the protein concentration.

Unlike soy and milk from which protein can be readily extracted andconcentration, heretofore it has not been possible to readily extractand concentrate protein from oats. As such, oat protein is not acommercially available ingredient or commodity like soy or milk protein.

SUMMARY OF THE INVENTION

An embodiment of the invention is directed to a method of preparing anoat protein and fiber product. A base formulation is prepared having amajor amount of an oat material or waxy barley hybrid. The baseformulation is mixed water to form a slurry.

At least one enzyme is mixed into the slurry. The at least one enzyme iscapable of facilitating sugar formation and thinning of the slurry. Theslurry is cooked to convert the slurry into a first intermediate producthaving a DE of between about 20 and 90.

The first intermediate product is diluted with water to form a secondintermediate product. The second intermediate product is heated. A firstsolids slurry is recovered from the second intermediate product using aclarifying centrifuge.

The first solids slurry is dried to form a dried product. The driedproduct has a protein concentration of between about 30 weight percentand about 90 weight percent and a total dietary fiber concentration ofless than about 5 weight percent.

Another embodiment of the invention is directed to a method of preparingan oat protein and fiber product. A base formulation is prepared havinga major amount of an oat material or waxy barley hybrid. The baseformulation is mixed with water to form a slurry.

At least one enzyme is mixed into the slurry. The at least one enzyme iscapable of facilitating sugar formation and thinning of the slurry. Theslurry is cooked to convert the slurry into a first intermediate producthaving a DE of between about 20 and 90.

The first intermediate product is diluted with water to form a secondintermediate product. The second intermediate product is heated. A firstsolids slurry is recovered from the second intermediate product using aclarifying centrifuge. At least one enzyme is added to the first solidsslurry. The first solids slurry is centrifuged to recover a secondsolids slurry.

The second solids slurry is dried to form a dried product. The driedproduct has a protein concentration of between about 30 weight percentand about 90 weight percent and a total dietary fiber concentration ofless than about 5 weight percent.

Another embodiment of the invention is directed to an oat protein andfiber product that includes an enzymatically and heat process oatmaterial, wherein the oat material is whole oat flour, low bran oatflour, patent oat flour, partially milled oats, oatmeal and combinationsthereof.

The oat protein and fiber product has a protein concentration of betweenabout 30 weight percent and about 90 weight percent and a total dietaryfiber concentration of less than about 5 weight percent. The oat proteinand fiber product has a moisture content of between about 5 percent andabout 10 percent.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of embodiments and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments andtogether with the description serve to explain principles ofembodiments. Other embodiments and many of the intended advantages ofembodiments will be readily appreciated as they become better understoodby reference to the following detailed description. The elements of thedrawings are not necessarily to scale relative to each other. Likereference numerals designate corresponding similar parts.

FIG. 1 is a chart of chemical analysis of several product preparedaccording to Example 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the invention is directed to forming a condensed, highsolids syrup with unique sweetening and flavoring characteristics froman oat-based functional syrup. The term functional indicates that theoat-based functional syrup has certain characteristics that make thisproduct useful in fabricating food products and beverages.

As the product thereby produced using the concepts disclosed herein isfabricated from oats, it is perceived as being more valuable than syrupsmay from other materials such as soy.

The oat-based functional syrup of the invention has several advantagesover prior art syrup bases. The oat syrup of the present invention issubstantially flavorless. The oat syrup of the present invention mayhave a nearly white color. Additionally, the oat syrup may exhibitdesirable sweetness, texture, and mouthfeel characteristics when formedinto food products such as non-dairy frozen confections withoutexogenous sweeteners, stabilizers, emulsifiers, or proteins, which arecommonly used in prior art non-dairy frozen confections.

As used herein, the term “mouthfeel” refers to a creamy sensation that aperson experiences in one's mouth upon consuming conventional ice cream.As used herein, the term “exogenous” refers to components that are addedto prior art food products and beverages to supplement or modify thecharacteristics of the prior art food products and beverages.

The properties of the oat-based functional syrup are dictated by theparticular oat or grain components selected. It has been found thatusing a low bran flour, which is substantially reduced in bran whileretaining soluble fiber glucans, provides the food products andbeverages with desired characteristics.

The term “bran,” as used herein, refers to the dark fibrous componentfound in ground oat flour. The typical compositional analysis of lowbran oat flour is similar to whole oat flour for moisture, protein, andfat as illustrated in Table 1, which is set forth below.

TABLE 1 Composition Whole Low Bran Fine (weight percent) Oat Flour OatFlour Oat Flour Moisture 11 11 10 Protein 18 15 10 Fat 7 7 6 TotalDietary Fiber 9 10 4-7 Beta-Glucan 4 7 2-4

While it is also possible to use oats or grains having a significanthull, bran or husk portion to formulate the oat-based functional syrup,syrup formed from these materials may need to be separated frominsoluble branny particles present in the oat-based functional syrupbefore the food product or beverage is produced from the syrup.

As an alternative to using the oats in the form of flour, it is alsopossible to practice the present invention with other forms of oats,such as rolled oats, partially milled oats, and oatmeal. These variousforms of oats are collectively identified as “oat material”.

One particular oat flour possessing a low level of bran or hull materialis fine oat flour. Fine oat flour is a fraction of the whole oat flourobtained from a sieving or air classification process.

The typical compositional analysis of fine oat flour is similar to wholeoat flour for moisture, protein, and fat, as illustrated in Table 1.Fine oat flour also retains a substantial percentage of the solublefiber that is present in whole oat flour. However, fine oat flourcontains less bran or insoluble fiber and more starch than whole oatflour.

The various fractions formed in the oat milling stream produce foodproducts and beverages with varied characteristics. The fractions highin soluble fiber, including whole oat flour and oatmeal, tend to givevery smooth and somewhat “dry” texture to soft-serve frozen dessert,while those higher in starch content tend to provide more sweetness.

It will be apparent to those skilled in the art that a desired set offinished product characteristics may be obtained by selecting anappropriate oat starting material or blend of available oat millingfractions. For example, the frozen confection may be formed from amixture of fine oat flour and whole oat flour. Oat mill productspossessing these characteristics can be obtained from various sourcesincluding Conagra, Inc. (Council Bluffs, Iowa) or Grain Millers(Minneapolis, Minn.).

It has also been found that a waxy barley hybrid flour also providesadvantageous results when used with the present invention. The waxybarley hybrid is a hull-less barley that may be selected from theprowashneupana variety, which can be obtained from Conagra, Inc.(Council Bluff, Iowa). The typical compositional analysis for theprowashneupana waxy barley hybrid is set forth in Table 2.

TABLE 2 Composition Waxy Barley (weight percent) Hybrid Flour Moisture14 Protein 20 Fat 7 Total Dietary Fiber 29 Beta-Glucan 14

Other starch sources can be used in conjunction with the oat flour orwaxy barley hybrid flour to adjust the flavor and sweetness of the foodproducts and/or beverages. While other starch sources may be used in thepreparation of the food products and beverages, the other starch sourcesmay only represent a minor portion of oat or grain material (up to 49weight percent) that is used to prepare the food products and beverages.

The oat flour and the waxy barley hybrid flour comprise a major portionof the oat or grain material (50 weight percent or more) that is used toprepare the oat-based functional syrup. In certain embodiments, the oatflour and the waxy barley hybrid flour comprise between about 50 andabout 80 weight percent of the material used to prepare the oat-basedfunctional syrup.

Examples of starch sources that are suitable for use in the presentinvention include flours, such as corn flour, wheat flour, rice flour,and potato flour. It is believed that the addition of other starchsources to the oat flour or waxy barley hybrid flour does not affect thefunctional properties of the food products and beverages, such astexture and mouthfeel characteristics.

As a preliminary step in the preparation of the oat-based functionalsyrup, the oat flour or waxy barley hybrid flour is milled to a finegranulation. Next, the ground material is subjected to a separationtechnique to remove the larger size particles.

The separation technique may remove substantially all of the groundmaterial that is larger than U.S. #100 mesh. In certain embodiments, theseparation technique removes substantially all of the ground materialthat is larger than U.S. #250 mesh.

Since the bran portion of the oat material typically has a particle sizethat is greater than this range, a significant portion of the branportion may be removed from the oat material through the separationtechnique. In certain embodiments, the separation technique reduces theconcentration of the bran component by at least 30 weight percent. Inother embodiments, the separation technique reduces the concentration ofthe bran component by at least 50 weight percent.

The presence of the bran may cause the syrup and subsequent productsmade from the syrup to be darker in color. Removal of the insolublefiber results in a lighter colored syrup when cooked by the proceduredelineated below. Using an oat material with these characteristics mayalso enhance the texture of the syrup product.

Additionally, using an oat material with these characteristics mayremove the need for a filtration step that was previously required toproduce a syrup product with desirable characteristics. This is a majorprocessing advantage since it is far easier to remove and prevent theeffects of the bran in the syrup prior to the hydrolysis process. Afinal filter may be done but it is not a required step, only a qualityassurance step.

Separation may be performed with sieve screening or air classification.While both sieve screening and air classification result in very smallsize material, in certain embodiments sieve screening may result in ahigher quality product.

The starch sources are mixed with the oat material to prepare asubstantially homogeneous base formulation. A person of ordinary skillin the art will appreciate that the oat material and the starch sourcesmay be mixed together before or after the grinding and separating steps.

A slurry is formed by mixing the base formulation into water in anamount that is effective to provide a solids level of between about 25percent and about 33 percent on a dry matter basis. In certainembodiments, the water is potable tap water that is provided at atemperature of about 10° C.

Changing the solids level may allow the sweetness of the oat-basedfunctional syrup to be adjusted. For example, increasing the solidslevel may cause an increase in the starch component, which may increasethe sweetness of the oat-based functional syrup.

The cook process may include a one-step procedure. An advantage of theone-step procedure is a reduction of processing time. Surprisingly, thiscombined enzyme procedure also results in a thinner syrup and a morerapid sugar formation.

An advantage to this cook process is the minimization of browningproducts normally formed in cook processes containing high reducingsugar. These products are common and form by the well-known Maillardreaction of reducing sugars and protein. When these off-colors aregenerated, it may be necessary to use reaction processes like activatedcharcoal to reduce the off-color.

The oat slurry or mixture may be cooked at as low a temperature aspossible to minimize flavor defects from bran as well as othercomponents of the oat flour (protein, fat, etc.). In certainembodiments, the cook temperature is between about 60° C. and about 70°C. In other embodiments, the cook temperature is between about 65° C.and 70° C. In still other embodiments, the cook temperature is about 68°C. Using temperatures in excess of this range (i.e., above 70° C.) mayresult in flavor and color defects.

The heating to the cook temperature may be done relatively slowly over aperiod of greater than about 15 minutes. In certain embodiments, theheat to the cook temperature may be done over a period of time ofbetween about 30 minutes and about 60 minutes. Heating of this period oftime may minimize the development of off flavors.

Using glucoamylase in conjunction with alpha-amylase may result in animproved thinning or liquefying action. The combined use of glucoamylaseand alpha-amylase may also produce rapid sugar formation from the oatmaterial. Additional glucoamylase can be added for higher conversion ofstarch to sugar and a higher sweetness level.

This procedure may result in a higher conversion rate to glucose and asavings in processing time. By decreasing the total thermal exposure ofthe oat base, the formation of off-flavors from remaining bran and othercomponents in the oat flour may be reduced.

The fine oat flour may be added along with a standard amount of lowtemperature active alpha-amylase (Genencor SPEZYME LT-75 or Novo BAN)plus an increased amount of glucoamylase that is about twice theconventionally recommended concentration. The enzymes work inconjunction to increase the rate at which glucose is formed.

In certain embodiments, the alpha-amylase may be alpha-1,4-glucan,4-glucanohydrolase, which is derived from Bacillus subtilis. Thealpha-amylase may not only produce liquefaction in a random fashion overa broad range of temperatures (between about 65° C. and 92° C.) but alsoretain its activity when used at temperatures of less than 80° C.

The alpha-amylase may be added to the slurry at a rate of between about0.50 and 1.25 grams per pound of oat material. In certain embodiments,the alpha-amylase is added at a concentration of about 0.75 grams perpound of oat material. The alpha-amylase may be food gradealpha-amylase, which can be obtained from Genencor International(Rochester, N.Y.) under the designation SPEZYME LT-75.

The dextrin may be converted into glucose using glucoamylase. Theglucoamylase is also referred to as fungal 1,4-alpha-D-glucanglucohydrolase, which can be obtained from Genencor International(Rochester, N.Y.) under the designation SPEZYME GA 300.

The glucoamylase may be added to the slurry at a rate of between about0.50 and 5.0 grams per pound of oat material. In certain embodiments,the glucoamylase is added to the slurry at a rate of about 2.15 gramsper pound of oat material.

By increasing the glucoamylase concentration, it may be possible toattain higher glucose levels. Such higher glucose levels may be requiredfor taste in a shorter time and reduce or eliminate off-flavors formedduring the longer hold times normally employed for the glucoamylase.

Using the one-step procedure of the present invention may result in asignificant reduction in the total processing time, which not onlyreduces the processing costs but also reduces the off-flavors generatedby prolonged exposure of the oat-based functional syrup to increasedtemperatures.

After the syrup product obtains a desired degree of sweetness, the syrupproduct may be cooled to a temperature of less than about 30° C. toprovide the oat-based functional syrup with a desired conversion level.In certain embodiments, the syrup product may be cooled to a temperatureof approximately 10° C.

The syrup product is clean and bland with no off-flavors. If it isdesired to increase the fructose concentration in the oat-basedfunctional syrup, the oat-based functional syrup may be subjected to anisomerization step using techniques that are conventionally known in theart.

As noted above, producing an oat-based functional syrup that has anearly white color enhances the ability to incorporate the oat-basedfunctional syrup into a variety of products. It has been found thatsubjecting the oat-based functional syrup to clarification lightens thecolor of the oat-based functional syrup so that the oat-based functionalsyrup is nearly white.

Depending on the product that is to be made with the oat-basedfunctional syrup, the oat-based functional syrup may be diluted withwater to have a consistency (about 14 weight percent solids) that issimilar to milk prior to performing clarification. Alternatively, theoat-based functional syrup may be concentrated to have a solidsconcentration that is greater than about 30 weight percent.

During the clarification step, the oat-based functional syrup may be runthrough a simple milk clarifier, which is also known as a creamseparator. The oat-based functional syrup exiting the milk clarifier isalmost white in color.

The extent to which the color of the oat-based functional syrup islightened may depend upon the residence time of the oat-based functionalsyrup in the milk clarifier. A longer residence time may result in apaler, weaker colored product that is similar to skim milk.

The length of the clarification process may also depend on the G forceused in the clarifier. For example, subjecting the oat-based functionalsyrup to a G force of about 2,000 G for less than one minute may removea significant amount of suspended material. Higher G forces (4,500 G)result a paler, lighter colored product. The amount of force imparted ina conventional clarifier may be between 7,000 and 8,500 G.

Product resulting from the clarification step may have an improvedcolor. For example, a white product is easier to color. Some improvementin taste is also apparent, especially in a diluted or milk formula (14weight percent solids). However, it is been found that extensiveclarification of the syrup intended for frozen desserts may remove someof the desired texture qualities—smoothness and mouthfeel—and,therefore, may not be recommended.

The oat-based functional syrup may be used to prepare food productsand/or beverages. The oat-based functional syrup may then be flavored asdesired using flavoring ingredients that are known in the art such asvanilla or cocoa.

The flavor of the oat-based functional syrup may be enhanced by theaddition of a small concentration of a flavor enhancer. Various flavorenhancers are known in the art and are selected based upon theparticular flavoring ingredients that are used in the food productsand/or beverages.

It is also possible to enhance the flavor of the food products and/orbeverages made from the oat-based functional syrup by adding salt in aconcentration of up to 1 weight percent. In certain embodiments, thesalt is provided at a concentration of about 0.35 weight percent of theoat-based functional syrup.

Adding salt to the oat-based functional syrup after the oat-basedfunctional syrup is formed may minimize off-flavors resulting from theaddition of the salt while the oat-based functional syrup is beingprepared.

After the above basic conversion steps are performed and the desiredconversion level (low DE equivalent to about 20 or high DE equivalent toabout 60) or sweetness level, the slurry may be run through a separatorto remove any coarse solids while leaving other components that are moresoluble such a protein, some fiber and fat (naturally emulsified). Incertain embodiments, the separator is a decanter.

The decantant material may be transferred by pumping to an evaporatorsystem. The evaporator system may have a variety of configurations,examples of which include single effect, double effect and tripleeffect.

To allow holding the decantant material in a surge vessel prior toevaporation, the decantant material can be pasteurized. An example ofone such suitable pasteurization technique includes high temperatureshort time (HTST) pasteurization.

The solids content of the oat-based functional syrup may be increased byreducing the moisture content of the product. An example of one suitabletechnique that may be used to reduce the moisture content isevaporation. In certain embodiments, the evaporation may be performed ata temperature of about 50° C. and a vacuum of about 70 centimeters ofmercury.

In some applications it may be desirable to use a syrup with a lowersugar level to primarily function in food formulations to bindingredients with the syrup such as in food bars. In such situations, thesyrup may be between about 25 and 50 percent as sweet as a fullyconverted syrup. In a fully converted syrup, substantially all thestarch has been enzymatically converted to sugars. The syrup industryalso uses the reducing sugar content divided by total solid as anexpression of DE.

These lower sweetness syrups are commonly referred to in the industry aslow dextrose equivalent (“DE”) syrups. The dextrose equivalent is thepercent solids measured as dextrose divided by the total starch solids.The syrup industry also uses the reducing sugar content divided by totalsolid as an expression of DE.

Syrups with a DE of 42 are most common but higher (DE 60) and lower (DE26) are used for specific applications as well. Low DE syrups representpartial conversion to lower levels of sugars as glucose or maltose.

A slurry is formed by mixing oat flour with water to provide arelatively low solids. In certain embodiments, the slurry has an oatflour concentration of about 15 weight percent. This lower solidsformulation is converted as is discussed in U.S. Pat. No. 6,685,974.

The converted mixture is decanted as discussed above and then subjectedto mechanical separation. In certain embodiments, the mechanicalseparation is done using a centrifuge. An example of one such centrifugethat may be used in conjunction with the mechanical separation is astacked disk centrifuge, which is commercially available from a varietyof companies such as Alfa Laval. The mechanical separation processenables finer material to be removed from the decantant. The clarifieddecantant thereby is more similar to conventional corn syrup.

The lower solids concentration of about 15 weight percent (or in certainembodiments about 12 weight percent) results in a much less viscousslurry and conversion syrup than higher solids formulations whichsignificantly increases the ability of the centrifuge to remove solidsand result in a higher clarified product. The clarified product is alsoless turbid.

The slurry having a solids concentration of about 15 weight percent isconverted to, for example, 4.2 weight percent glucose, the enzymereaction largely stopped by cooling the slurry to less than about 27° C.The cooled slurry is then centrifuged using the decanter to remove thecoarser or heavier suspended material.

The viscosity of the decantant is further reduced and all enzymeactivity stopped by heating it to a temperature of greater than 82° C.In certain embodiments, the decantant is heated to a temperature ofbetween about 82° C. and about 96° C. Next, the decantant is transferredto a stacked disk centrifuge and metered such as to further removesuspended or colloidal material. This process resulted in a clarifiedlight syrup.

Alternatively, the final clarified light syrup is then heat treated perHTST (high temperature short time pasteurization) or similar treatmentsso as to ‘kill’ the enzyme activity by exceeding 82° C. and holding atsuch temperature for the kill to be substantially effective. In certainembodiments, the hold time was up to about 5 minutes. This process alsoserves to pasteurize the product. A longer hold time or exposure to heatcan be done at this stage of the process without deleterious effects.The glucose content changed slightly to about 5.2 weight percent.

The syrup is then condensed to 50 Brix and caramelized as below or,alternatively, simply condensed without the caramelization step to asolids concentration of at least about 80 weight percent for a low wateractivity, microbially stable product. In certain embodiments, the finalproduct has a DE of about 42. Lower DE syrups are simply cooled to stopsugar formation sooner to result in a lower sugar content.

Dilute slurry syrups can also be made using the process described abovebut starting at a higher solids (such as about 28 weight percent). Next,the slurry is converted using the process described in Whalen et al.,U.S. Pat. No. 6,685,974. Thereafter, the product may be diluted todecrease the solids concentration (such as by the addition of water at aratio of about 1:1) prior to the centrifuge steps to make the clarifiedsyrup product. It has been found that this is a more efficient way tomake the initial conversion syrup.

Upon achieving a Brix reading of about 50, the vacuum is removed and theoat-based functional syrup may be heated to a temperature of about to82° C. Such a process has been found to produce caramelization of theoat-based functional syrup.

It has been found that the oat-based functional syrup will continue tolose virtually all ‘oaty’ or ‘grainy’ type flavors as the oat-basedfunctional syrup is condensed. Upon continued evaporation and increasingthe temperature, the oat-based functional syrup will develop distinctmaple then caramel flavors.

In certain embodiments, the final condensed oat-based functional syruphas a concentration of between about 65 and 72 Brix. The Brix and solidslevel can continue to be increased to higher levels if desired such asto attain a solids concentration of between about 78 and 82 weightpercent.

It has been discovered that holding the syrup at higher temperaturesstarting at 50 Brix, the oat-based functional syrup will develop strongcaramel flavors as well as the appearance of caramel candy (caramelcolor). This is accomplished by holding the 50 Brix syrup at a producttemperature of between about 82° C. and 93° C. without vacuum, forbetween about 15 and 20 minutes in a batch or single effect evaporator.

The oat-based functional syrup will develop the desired caramel flavorand color. The intensity of the color is affected by how long the syrupis held at this higher temperature. After the caramelization step, thetemperature is reduced to between about 49° C. and 54° C. and the vacuumresumed at up to about 69 centimeters Hg.

The oat-based functional syrup will then quickly attain a solids levelof 65 to 77 Brix (whatever is desired). In a double effect evaporator,the solids and flavor will be developed in the first evaporator andfinished in the second evaporator to the desire solids level.

Another embodiment of the invention is directed to preparing an oatprotein and fiber product. As an initial step in preparing this product,an oat-based initial syrup was produced using a process that is similarto the process set forth in Whalen et al., U.S. Pat. No. 6,685,974. Inthis syrup, the starch was substantially converted to glucose, whichprovided the syrup with a glucose concentration of about 18 weightpercent.

Next, the syrup is diluted with water to form a mixture. In certainembodiment, the ratio of water to syrup is between about 3:1 to about1:3. In other embodiments, the ratio of water to syrup is about 1:1.

The mixture is centrifuged. In certain embodiments, the centrifuge is adecanting centrifuge such as a Penwalt P660. The resulting decantersolids have a protein concentration of between about 15 weight percentand about 30 weight percent on a dry weight basis. In other embodiments,the decenter solids have a protein concentration of about 20 weightpercent protein on a dry weight basis.

The decanter solids have a total dietary fiber concentration of betweenabout 10 weight percent and about 30 weight percent. In otherembodiments, the total dietary fiber concentration of the decantersolids is between about 16 weight percent and about 20 weight percent.

The mixture is heated to a temperature is greater than about 65° C. Inother embodiments, the temperature is between about 71° C. and about 82°C. The decantant liquid is then clarified. An example of one suitabledevice that may be used for clarification is a clarifying centrifugesuch as a stacked disc de-sludging centrifuge (Westfalia SB 7). Theclarifying centrifuge may have a timed hydraulic purge to clean thecentrifuge bowl. The resulting material was a high solids slurry.

The high solids slurry is then dried. An example of one suitable dryingtechnique is spray drying. The spray dried product has a proteinconcentration of between about 40 and 50 weight percent on a dry basis.The spray dried product has a total dietary fiber content of less thanabout 3 weight percent. This total dietary fiber concentration is muchlower than the fiber content of the decanter solids. The remainder ofthe spray dried product is carbohydrate as starch or sugar.

Based upon the preceding results, it is believed that the decanterfunctions to remove the fibrous material from the oat conversion syrup.Both the decanter solids and the clarifying centrifuge solids containedbetween about 16 and 20 weight percent oat lipid (oat oil).

Sweetener syrups used for food formulations are commonly only partiallyconverted. The degree of conversion is expressed as the DE. DE is equalto the amount of reducing sugars as glucose divided by the totalreducing sugar as starch and dextrins and converted to percent.

A widely used syrup has a DE of about 42, wherein about one-half of thesyrup is primarily glucose and maltose. The lower the DE, the lower thesugar content and sweetness level. Lower DE syrups are valued for theirbinding qualities in such products as cereal bars.

Unlike the conversion discussed above, these lower conversion syrupscontain dextrins and starch that can be separated out with the othersolids by the clarifying centrifuge. Such a process substantiallydilutes the protein content. In certain embodiments, the protein contentis reduced by about one half. This process results in a dried productcontaining an oat protein concentration of only between about 20 weightpercent and about 25 weight percent.

To circumvent this problem, a second conversion is performed on thesolids slurry obtained from the clarifying centrifuge to convert theremaining starch and dextrins to dextrose. Solids from the clarifyingcentrifuge are collected at up to a level of about 25 weight percent ofthe total syrup being centrifuged.

Alpha-amylase is added to the slurry. In certain embodiments, thealpha-amylase is added at a concentration of between about 0.05 weightpercent and about 0.20 weight percent. In other embodiments, thealpha-amylase is added at a concentration of between about 0.07 weightpercent and about 0.14 weight percent.

The mixture is heated to solubilize any residual starch. In certainembodiments, the temperature is greater than about 65° C. In otherembodiments, the temperature is between about 71° C. and about 82° C.

The mixture is maintained at this temperature for a sufficiently longperiod of time to solubilize the residual starch. In certainembodiments, the mixture is maintained at the temperature for more thanabout 15 minutes. In other embodiments, the mixture is maintained at thetemperature for about 30 minutes. The mixture is then cooled to atemperature of less than about 65° C. In certain embodiments, themixture is cooled to a temperature of about 60° C.

Glucoamylase is added to the mixture. In certain embodiments, theglucoamylase is added at a concentration of between about 0.05 weightpercent and about 0.20 weight percent. In other embodiments, theglucoamylase is added at a concentration of between about 0.07 weightpercent and about 0.14 weight percent.

Mixing is continued until the mixture is substantially homogeneous. Themixture is held at this temperature until the glucose level is stable. Afactor in the length of the hold time may be the concentration ofglucoamylase that is used. In certain embodiments, the hold time isbetween about 30 and 120 minutes.

The secondary converted material is then centrifuged. In certainembodiments, the centrifuge is a clarifying centrifuge. Since the starchand dextrins have been converted to soluble glucose, these componentsmay remain with the liquid instead of separating out with the clarifyingcentrifuge solids.

The protein content is not diluted and achieves a level of at leastabout 40 percent on a dry weight basis. The centrate containing theglucose is returned to the process by (1) adding it back to the initialconversion as make-up water or, (2) returned as dilution water to theinitial syrup for decanting. In this manner none of the sugar is lost inthe process.

The protein concentration of the product can be increase by performing awash. The wash can be done by diluting the sludge from the clarifyingcentrifuge with water and re-centrifuging.

As long as the carbohydrate in the sludge is soluble sugar, it will beremoved with the liquid and not separate as a solid. The protein contentwill increase as these diluting soluble components are reduced.

The product and method of the present invention are described in thefollowing examples. These examples are provided as an illustration ofthe invention and are not intended to limit the invention.

EXAMPLE 1

A single effect, batch evaporator was fed a centrifuged decantantoat-based functional syrup with a solids level of about 25 weightpercent and a glucose level of between about 16 and 18 weight percent(or a DE of about 60) to a level in the evaporator which covered theheating elements at the bottom of the evaporator. In certainembodiments, the evaporator's working volume was approximately 38liters.

The low solids oat-based functional syrup was gradually fed into theevaporator as water was evaporated at 49° C. with a pressure of betweenabout 51 and 69 centimeters Hg vacuum until the batch evaporator reachedthe working volume.

When the solids content achieved 51 Brix, the vacuum was shut off andthe product temperature was increase to between about 80° C. and 88° C.The product thereafter changed from a strong cereal off-flavor to abland flavor and continued to produce maple and caramel flavors with asimultaneous change in color from the original tan to a caramel color.

Stronger caramel flavor was produced by continuing the conditions forabout 20 minutes until a strong caramel flavor devoid of burned noteswas produced. The temperature was then reduced to about 54° C. and thevacuum resumed at about 69 centimeters Hg at which the solids levelrapidly achieved 70 Brix.

A similar result was obtained using a double effect evaporator operatedwith continuous feed wherein the base syrup was pre-heated to about 88°C., operated until the Brix level was about 50 and then finished in thesecond evaporator at about 60° C. and a vacuum of about 51 centimetersHg.

EXAMPLE 2 Clarified Syrup Product

A syrup product was produced as in Example 1 except the syrup basematerial was subjected to higher centrifugal force using a stacked diskseparator (Alfa Laval) to reduce suspended solids by about 50 percentmore than that in Example 1. This material was then fed to a singleeffect batch evaporator to a level which covered the heating elements atthe bottom of the evaporator. The evaporator's working volume was about38 liters.

The product was evaporated as in Example 1. The condensed syrupresulting from the higher centrifugal force treatment of the basematerial had greater sweetness impact as evaluated by tasting theproduct and more intense caramel flavor than the product made perExample 1.

EXAMPLE 3 Lower Conversion Syrup

A syrup product was prepared using the process described in U.S. Pat.No. 6,685,974. The oat flour comprised 25 percent of the slurry on aweight to weight basis. The slurry was treated per the conversionprocess described in U.S. Pat. No. 6,685,974 to approximately one-halfthe sugar content of Example 1.

The sugar level was about 9 percent on a weight to weight basis asglucose and had a DE of between about 25 and 30. The reaction is stoppedby chilling the slurry to a temperature of between about 4° C. and 27°C. The cooled slurry was then centrifuged using the process set forth inExample 1.

Next, the centrate or liquid portion was heat-treated at a temperatureof at least about 82° C. using processes common in the industry such asplate and frame heat exchangers. In this manner, the sugar producingreaction was halted and lower DE maintained.

The centrate was then condensed using a process that was similar to theprocess set forth in Example 1 to produce a syrup with much lowersweetness and sugar content but having good binding properties formaking products such as food bars.

EXAMPLE 4 High Clarified, Lower Conversion Syrup

A syrup product was prepared using the process described in Whalen etal., U.S. Pat. No. 6,685,974. The oat flour comprised 15 percent of theslurry on a weight to weight basis. The slurry was treated using theconversion process discussed in Whalen et al., U.S. Pat. No. 6,685,974,to approximately one-half the sugar content of Example 1.

The sugar level was about 4.2 percent on a weight to weight basis asglucose and had a DE of between about 25 and 30. The reaction wasstopped by chilling the slurry to a temperature of between about 4° C.and 27° C. The cooled slurry was then centrifuged using the process setforth in Example 1.

Next, the centrate or liquid portion was heat-treated at a temperatureof at least about 82° C. using processes common in the industry such asplate and frame heat exchangers. In this manner, the sugar producingreaction was halted and lower DE maintained.

The centrate was then condensed using a process that was similar to theprocess set forth in Example 1 to produce a syrup with much lowersweetness and sugar content but having good binding properties formaking products such as food bars.

EXAMPLE 5 High maltose syrup

A base syrup slurry with a solids level of 25 percent on a weight toweight basis was produced using a process that is similar to the processset forth in Whalen et al., U.S. Pat. No. 6,685,974, except that fungalalpha-amylase was used instead of bacterial alpha-amylase.

After conversion using the process set forth in Whalen et al., U.S. Pat.No. 6,685,974, the sugar content of the slurry was approximately 40weight percent maltose and 60 weight percent glucose. Next, the slurrywas centrifuged and evaporated using the method set forth in Example 1.

The syrup product maintained the ratio of maltose to glucose and, as aresult, was less sweet since maltose is about 10 percent less sweet thanglucose. This type of syrup is desirable by food formulators who wish tolessen the sweetness impact of their product while retaining the highconversion syrup properties.

EXAMPLE 6 High Conversion Syrup

An oat-based initial syrup was produced using a process that is similarto the process set forth in Whalen et al., U.S. Pat. No. 6,685,974,wherein the starch is substantially converted to glucose (approximately18 weight percent glucose).

A slurry if formed by mixing an oat material and water. At least oneenzyme is mixed into the slurry. The at least one enzyme is capable offacilitating sugar formation and thinning of the slurry. The slurry iscooked to convert the slurry into a first intermediate product having aDE of between about 20 and about 90.

The first intermediate is diluted with water at a ratio of about 1:1 toform a second intermediate product. The second intermediate product washeated to a temperature of about 70° C.

The second intermediate product was then clarified using a clarifyingcentrifuge such as a stacked disc de-sludging centrifuge. A Westfalia SB7 de-sludging/clarifying centrifuge was used with a timed hydraulicpurge to clean the centrifuge bowl. The resulting material was a highsolids slurry.

This high solids slurry was dried by spray drying. The spray driedproduct had a moisture content of between about 5 percent and about 10percent, a protein content of between about 40 and 60 weight percent ona dry basis and a total dietary fiber concentration of between about 2and 4 weight percent, which is much lower than the fiber content of thedecanter solids. The remainder of the materials in the spray driedproduct is carbohydrate as starch or sugar.

EXAMPLE 7 High Conversion Syrup

An oat-based initial syrup was produced using a process that is similarto the process set forth in Whalen et al., U.S. Pat. No. 6,685,974,wherein the starch is substantially converted to glucose (approximately18 weight percent glucose).

At least one enzyme is mixed into the slurry. The at least one enzyme iscapable of facilitating sugar formation and thinning of the slurry. Theslurry is cooked to convert the slurry into a first intermediate producthaving a DE of between about 20 and about 90.

The first intermediate is diluted with water at a ratio of about 1:1 andcentrifuged using a decanting centrifuge (Penwalt P660). The resultingdecanter solids have a protein concentration of about 20 weight percenton a dry weight basis and a total dietary fiber concentration of betweenabout 16 weight percent and about 20 weight percent.

The decantant liquid is then clarified using a clarifying centrifugesuch as a stacked disc de-sludging centrifuge. A Westfalia SB 7de-sludging/clarifying centrifuge was used with a timed hydraulic purgeto clean the centrifuge bowl. The resulting material was a high solidsslurry.

This high solids slurry was dried by spray drying. The spray driedproduct had a protein content of between about 40 and 50 weight percenton a dry basis and total dietary fiber concentration of between about 2and 3 weight percent, which is much lower than the fiber content of thedecanter solids. The compositions of the components in the spray driedproduct are set forth in Table 3 below. The remainder of the materialsin the spray dried product is carbohydrate as starch or sugar.

TABLE 3 Composition Decanter Clarifier (weight percent) SolidsCentrifuge Protein 38.1 46 Lipid 20 14.2 Fiber 18 1.2 Ash 4.5 0.86

Based upon the preceding results, it is believed that the decanterfunctions to remove the fibrous material from the oat conversion syrup.Both the decanter solids and the clarifying centrifuge solids containedbetween about 16 and 20 weight percent oat lipid (oat oil).

EXAMPLE 8 Lower Conversion Syrup

A second conversion was performed on the solids slurry obtained from theclarifying centrifuge in Example 6 to convert the remaining starch anddextrins to dextrose. Solids from the clarifying centrifuge arecollected at a level of about 25 weight percent of the total syrup beingcentrifuged.

Alpha-amylase was added at a concentration of between about 0.07 and0.14 weight percent. The mixture was heated to a temperature of betweenabout 71° C. and 82° C. for approximately 30 minutes to solubilize anyresidual starch. Thereafter, the mixture was cooled to a temperature ofabout 60° C.

Glucoamylase was added to the mixture at a concentration of betweenabout 0.07 and 0.14 weight percent. After being mixed untilsubstantially homogeneous, the mixture was held until the glucose levelwas stable. A factor in the length of the hold time may be theconcentration of glucoamylase used. In certain embodiments, the holdtime is between about 30 and 120 minutes.

The secondary converted material was then centrifuged by passing througha clarifying centrifuge. Since the starch and dextrins have beenconverted to soluble glucose, these components may remain with theliquid instead of separating out with the clarifying centrifuge solids.

The protein content was not diluted and achieved a level of at leastabout 40 percent on a dry weight basis. The centrate containing theglucose was returned to the process by (1) adding it back to the initialconversion as make-up water or, (2) returned as dilution water to theinitial syrup for decanting. In this manner none of the sugar is lost inthe process. See Tables 3 and 4. The remainder of the material iscarbohydrate or sugars.

TABLE 4 Clarifier Clarifier Centrifuge Centrifuge Composition Decanterwithout second with second (weight percent) Solids conversion conversionProtein 38.1 24 44.2 Lipid 20 11.4 16.5 Fiber 18 1.8 2.28 Ash 4.5 0.841.36

EXAMPLE 9 Amino Acid Profile

Another benefit of the oat protein and fiber product produced accordingto the methods described herein is that the oat protein and fiberproduct includes advantageous levels of several amino acids that arebeneficial for consumption by humans.

FIG. 1 includes a chart that provides the amino acid profiles of severaloat protein and fiber products produced according to Example 6. Inaddition to providing the amino acid levels that were measured, thischart also includes the amino acid levels converted to a 100 gramprotein sample, which is similar to the manner in which amino acidlevels are conventionally reported. FIG. 1 also includes the levels ofvarious sugars, fat, ash, protein, moisture and total dietary fiber(TDF) for the samples.

While the chart indicates that several of the amino acids haverelatively high concentrations, an even more important indication fromthe chart is that the oat protein and fiber product has a balanced aminoacid profile. This means that each of the amino acids included in thischart are present at more than trivial levels. This amino acid profileis quite different and superior to the amino acid profile of other highprotein ingredients that are typically used in food products.

In the preceding detailed description, reference is made to theaccompanying drawings, which form a part hereof, and in which is shownby way of illustration specific embodiments in which the invention maybe practiced. In this regard, directional terminology, such as “top,”“bottom,” “front,” “back,” “leading,” “trailing,” etc., is used withreference to the orientation of the Figure(s) being described. Becausecomponents of embodiments can be positioned in a number of differentorientations, the directional terminology is used for purposes ofillustration and is in no way limiting. It is to be understood thatother embodiments may be utilized and structural or logical changes maybe made without departing from the scope of the present invention. Thepreceding detailed description, therefore, is not to be taken in alimiting sense, and the scope of the present invention is defined by theappended claims.

It is contemplated that features disclosed in this application, as wellas those described in the above applications incorporated by reference,can be mixed and matched to suit particular circumstances. Various othermodifications and changes will be apparent to those of ordinary skill.

1. A method of preparing an oat protein and fiber product comprising: preparing a base composition comprising an oat material; mixing the base composition and water to form a slurry; mixing at least one enzyme into the slurry, wherein the at least one enzyme facilitates sugar formation and thinning of the slurry; cooking the slurry to convert the slurry into a first intermediate product having a dextrose equivalent (DE) of between about 20 and 90; diluting the first intermediate product with water to form a second intermediate product; recovering a decanting centrifuge solids slurry from the second intermediate product by passing the second intermediate product through a decanting centrifuge; heating the decanting centrifuge solids slurry; recovering a clarifying centrifuge solids slurry from the heated decanting centrifuge solids using a clarifying centrifuge; and drying the clarifying centrifuge solids slurry to form a dried product, wherein the dried product has a protein concentration of between about 30 weight percent and about 90 weight percent and a total dietary fiber concentration of less than about 5 weight percent.
 2. The method of claim 1, wherein the oat material comprises whole oat flour, low bran oat flour, patent oat flour, partially milled oats, oatmeal or combinations thereof.
 3. The method of claim 1, wherein the at least one enzyme comprises alpha-amylase or glucoamylase.
 4. The method of claim 1, wherein the water is mixed with the first intermediate product at a ratio of about 1:1.
 5. The method of claim 1, wherein the decanting centrifuge solids slurry has a protein concentration of between about 15 and 30 weight percent on a dry weight basis and a total dietary fiber concentration of between about 10 and 30 weight percent
 6. The method of claim 1, wherein the decanting centrifuge solids slurry is heated to a temperature of between about 71° C. and about 82° C.
 7. The method of claim 1, and further comprising washing the clarifying centrifuge solids slurry to increase a protein concentration thereof and produce a washed clarifying centrifuge solids slurry.
 8. The method of claim 1, wherein the drying comprises spray drying.
 9. The method of claim 1, wherein the dried product has a protein concentration of between about 50 weight percent and about 60 weight percent.
 10. The method of claim 1, wherein the dried product has a moisture content of between about 5 percent and about 10 percent.
 11. A method of preparing an oat protein and fiber product comprising: preparing a base composition comprising an oat material; mixing the base composition and water to form a slurry; mixing at least one enzyme into the slurry, wherein the at least one enzyme facilitates sugar formation and thinning of the slurry; cooking the slurry to convert the slurry into a first intermediate product having a dextrose equivalent (DE) of between about 20 and 90; diluting the first intermediate product with water to form a second intermediate product; recovering a decanting centrifuge solids slurry from the second intermediate product by passing the second intermediate product through a decanting centrifuge; heating the decanting centrifuge solids slurry; recovering a clarifying centrifuge solids slurry from the heated decanting centrifuge solids slurry using a clarifying centrifuge; adding at least one enzyme to clarifying centrifuge solids slurry; centrifuging the clarifying centrifuge solids slurry to recover a third solids slurry; and drying the third solids slurry to form a dried product, wherein the dried product has a protein concentration of between about 30 weight percent and about 90 weight percent and a total dietary fiber concentration of less than about 5 weight percent.
 12. The method of claim 11, wherein adding the at least one enzyme to the decanting centrifuge solids slurry comprises: adding alpha-amylase to the decanting centrifuge solids slurry when the decanting centrifuge solids slurry is at a first temperature, wherein the alpha-amylase is added at a concentration of between about 0.07 weight percent and about 0.14 weight percent; and adding glucoamylase to the decanting centrifuge solids slurry when the decanting centrifuge solids slurry is at a second temperature, wherein the glucoamylase is added at a concentration of between about 0.07 weight percent and about 0.14 weight percent and wherein the first temperature is higher than the second temperature.
 13. The method of claim 12, wherein the mixture is maintained at the second temperature until a concentration of glucose remains substantially constant.
 14. The method of claim 11, wherein the oat material comprises whole oat flour, low bran oat flour, patent oat flour, partially milled oats, oatmeal or combinations thereof.
 15. The method of claim 11, wherein the at least one enzyme added to the slurry comprises alpha-amylase or glucoamylase.
 16. The method of claim 11, wherein the water is mixed with the first intermediate product at a ratio of about 1:1.
 17. The method of claim 11, wherein the decanting centrifuge solids slurry has a protein concentration of between about 15 and 30 weight percent on a dry weight basis and a total dietary fiber concentration of between about 10 and 30 weight percent.
 18. The method of claim 11, wherein the decanting centrifuge solids slurry is heated to a temperature of between about 71° C. and about 82° C.
 19. The method of claim 11, and further comprising washing the third solids slurry to increase a protein concentration thereof and produce a washed third solids slurry;
 20. The method of claim 11, wherein the drying comprises spray drying and wherein the dried product has a moisture content of between about 5 percent and about 10 percent.
 21. The method of claim 11, wherein the dried product has a protein concentration of between about 50 weight percent and about 60 weight percent. 